Method for obtaining viscose filament rayon with cyclically varying linear density called &#34;flame&#34; rayon, an installation for the realization of this method, and a product, obtained using this method and this installation

ABSTRACT

When to the spinning machine one or two individual installations for dying are joined suggested method allows production of dyed in one or two colours filament rayon with cyclically varying linear density.

The present invention concerns a method for obtaining viscose rayon withcyclically varying linear density called “flame” rayon yam, aninstallation for die realization of this method, and a product, obtainedusing this method and this installation.

Previous Slate of the Technology

The production of viscose rayon dates back as the beginning of theprevious century. Viscose filament rayon is a part of various types ofwhite or dyed fibers and yarns, as well as other fancy yams widely usedin the industry,

There is a method described in patent U.S. Pat. No. 5,890,355. Accordingto this method of and apparatus for production a thin thick effect yarnprovides a thin/thick effect by segmentwise stretching of a filamentaryprecursor yam,which is combined with a fully-stretched filamentaryprecursor yarn so that the latter supports the former. The combinationcan be effected by twisting, nub entanglement or winding of one yarnaround the other.

There is also a method for obtaining fancy yarns as described in theU.S. Pat. No. 4,258,542 based on bundle of fibrous elements. Disclosedis a bundle of fibrous elements, at least some of which are uneven inthe thickness in the axial direction thereof namely some of whichinclude thick portions having a larger sectional area and thin portionhaving a smaller sectional area. In these fibrous elements constitutingthe fibrous bundle, the thick portions have, in general, a higherdyeability than the thin portions, and in a fibrous bundle, these higherdyeability portions are formed substantially randomly at a distributionratio of at least 300 portions per 10 cm of the length of the fibrousbundle. This fibrous bundle is characterized in that it apparentlyresembles a fibrous bundle composed of fibrous elements uniform in ththickness and dyeability. Also a process and apparatus for manufacturingsuch fibrous bundles are disclosed.

Document EP 0848094 describes a fancy yarn, based on a process where afilament yam which is not fully drawn in sections and with thick/thinzones is brought together with an effect filament over its whole length.The filament yarn is fully drawn into an affect yarn. Also claimed is anapparatus with at least one eddy jet or at least one winding spindlewith a supply bobbin for effect filament where the filament are broughttogether, and a following drawing field for the combined yarn.

The combination of the two fibres is achieved through air blowing, andpressing one of the fibres over the other or by joint rewinding of bothfibres in one bobbin.

The main characteristic of the above-described known methods forobtaining of fancy yarn is that they are performed during textileprocessing of already spun fibres after their combination by means ofvarious methods in order to result in a new combined yarn, generallydefined as some kind of a fancy yarn, i.e. using two fibres to obtain ayarn different by type from the source fibres after the application ofone or a couple of additional, textile operations, using speciallyconstructed technical means.

There is no known method for obtaining viscose filament rayon withirregular thickness where the cyclically deviated linear density isformed directly as early as the stage of spinning.

There is a technology for the production of viscose rayon which includesthe following stages—FIG. 1: mercerization /1/, being processing of theinitial pulp (cellulose) with a concentrated solution of sodiumhydroxide (NaOH), resulting in alkali cellulose, which afterwards issubjected to destruction /2/, i.e. aging, where the degree ofpolymerization is decreased. This is followed by temperature reduction/3/ and dosing of the alkali cellulose amount for the production of onebatch of viscose /4/. The next stage is carbon-disulphide treatment /5/,which causes the alkali cellulose to transform into cellulose xanthate,whose most important property is that it is soluble in diluted solutionsof sodium hydroxide /6/. The cellulose solution of one batch is thenmixed and homogenized with the one from the previous and the followingbatch /7/, deaerated /7/, and filtered /8/ to remove the impurities.Then the viscose solution is fed under pressure for spinning to thespinning machines.

The stage of spinning is performed as the viscose solution from a mainpipeline under pressure is passed for spinning in a viscose pipecollector to each spinning machine /10/, where by means of synchronouslyactuated dosing pumps equal quantities of the viscose solution from thisviscose pipe collector are supplied to the spinnerets at each workingposition. The viscose solution then passes under pressure into a spinbath /11/ where as a result of the chemical reactions in coursetransforms into freshly-spun cellulose filament rayon fibers with aspecified/linear density/thickness depending on the quantity of dozedviscose solution.

Leaving the spin bath the freshly-spun cellulose passes consecutively tothe first /27-1 and then the second spinning devices /28-1/, and then itis arranged in the centrifuge /29-1, FIG. 3/. Further, the process isinterrupted as when the centrifuge is filled up to a specific volume,the fiber between the first and the second spinning devices is cut offand wound only on the first one. In meanwhile the centrifuge is stopped,the formed in it rayon cake is taken out, and it is again put intooperation. The fiber from the first spinning device is again transferredto the second one, and then passed, into the centrifuge to obtain thenext rayon cake.

In the production of dyed in mass viscose filament rayon to the readyfor spinning viscose solution is added a preliminary prepared pigmentsuspension consisting of one or a couple of pigments/ 9, FIG. 1/. Therequired quantity of the suspension is dosed and mixed with the viscoseinto homogenizer /10-1, FIG. 1/, thus causing the pigment particles todistribute uniformly throughout the entire volume of this solution. Thedyed and homogenized viscose solution after ward is subjected to theabove-described spinning operations.

This is followed by washing procedures /12/ where the freshly-spunviscose filament rayon rayon is treated with various solutions /13/toclear the residues of the spin bath, the sodium sulfate and sulfurresulted from the chemical reactions during spinning. The obtainedsemi-finished product is then dried /15/, conditioned /16/, rewound/17/,prepared for quality control inspection/18,19/ and packaging as afinished product finally.

Using this technology can be obtained white or dyed in mass viscosefilament rayon, uniform in thickness notwithstanding the length of thefiber. This to some extent is regarded as a disadvantage because only alimited range of products is obtained, which could not live up to thedemands of the textile industry for visually fancier yarns

There is an installation which puts into practice the above-describedmethod of production of viscose filament rayon obtaining a product withuniform thickness/linear density/ (FIG. 1). The installation includesthe range of technological operations and following units connectedserially mercerization unit /1/, aging unit/2/, unit for temperaturereduction/3/, a dosing unit for the amount of the alkali celluloseneeded for the production of one batch of rayon/4/; carbon-disulphidetreatment unit—treatment of the alkali cellulose with carbon-disulphideto obtain cellulose xanthate/5/, units for mixing and homogenization ofthe cellulose solution from one batch to the one from the previous andthe following batch/7/, deaeration unit /7/and filtering units forremoval of the impurities/8/.

In order to obtain dyed in mass viscose filament rayon m a connected tothe spinning machine individual dyeing installation /10-1 from FIG. 1/presented in details in FIG. 2, a pigment suspension is preliminaryprepared, which for the planned production cycle is stored in a specialtank /30/, it is dosed by means of a pump/31/ into the viscose Corningfrom viscose supplying, pipes 36 and 37 and the mixture enters ahomogenizer /32/, thus the pigment or pigment particles are distributeduniformly throughout the entire volume of the viscose solution. Thecoloured after the homogenization cellulose solution is fed underpressure to a viscose pipe collector /38/for spinning in the spinningmachine /10, FIG. 3/ to which dosing gear pumps 22 are joined, actuatedby one and the same power shaft 21 (FIG. 3).

The classically equipped spinning machine actuating is arranged by theuse of two electric motors. First motor 40-1, powered by feeding unit40-4, which through the first reduction gear 39-1 and the geartransmission system 39-3 is mechanically connected to the first spinningdevices 27-1, second spinning devices 28-1 and power shaft 21 to whichviscose solution dosing pumps 22 are joined.

The second electric motor 40-2, powered by the same feeding unit 40-4,through the second reduction gear 39-4 has a mechanical connection andtransmits motion to the arranging device 39-5, which transfers alreadyspun filament rayon to the centrifuge 29-1 of the spinning machine 10.

In this classically designed and well known installation, the spinningstage is carried out as the cellulose solution from a main pipeline/36—FIG. 2/ under pressure is fed into a Viscose pipe collector /37,FIG. 2/ to each spinning machine. This pipeline being permanently filledup with viscose solution under pressure for the prevention of gas phaseoccurrence. All viscose solution dosing gear pumps /22, FIG. 3/of aspinning machine /10/have a common actuation by one and the same powershaft /21/. The revolutions of this shaft defines the viscose solutionquantity transferred by each dozing pump from the viscose pipecollector/38/ to the spinnerets at each working position. Thisuniformity of dosing of the viscose solution is a result of thespecified and continuously controlled number of revolutions of powershaft /21/to which viscose dozing pumps are joined,

Further, the viscose solution coming out from the spinnerets enters aspin bath/11/ where, as a result of the chemical reactions in course,transforms into rayon filament fibers. Leaving the spin bath, thefreshly-spun cellulose as filament rayon fiber passes consecutively tothe first /27-1/ and then the second spinning devices /28-1/after whichit is arranged in the centrifuge/29-1. When the centrifuge is filled upto a definite volume, the fiber between the first and the secondspinning device is interrupted and wound only on the first one.Meanwhile the centrifuge is stopped, the formed in it rayon cake istaken out, and the centrifuge is put into operation again. When the sameis in operating mode the rayon filament fiber from the first spinningdevice is again transferred to the second spinning device and passed tothe centrifuge, thus starting the production of the next rayon cake.

An important especially of classically equipped spinning machine is thatits power feeding and the motors and the reduction gears actuation isconstantly balanced during the time of the spinning process realization,i.e. the revolutions of the power shaft/21/ actuating the viscose dozingpumps /22/and those of the spinning devices (27-1 and 28-2) are mutuallyconnected and in constant synchronization for the time of the wholespinning cycle for a definite type or rayon.

Thus in all working positions of one classically equipped spinningmachine depending on the chosen adjustment viscose filament rayon withone and the same thickness /linear density/ will be produced.

The textile industry needs new types of fibers and yarns, which incontrast to the existing ones, would make the articles visually fancier.

The purpose of the present invention is to suggest a method forobtaining of viscose filament rayon with cyclically varyingthickness/linear density/ and a product manufactured using this method,as well as an installation for the realization of the invented method,where fancy viscose filament rayon is obtained directly as early as thestage of the spinning of the rayon filament fiber without usingadditional stages or specially designed machines.

Nature of the Invention

According to the invention a method for obtaining of viscose rayonfilament yam with cyclically varying thickness/linear density issuggested, including the following stages/FIG. 1/: the initial celluloseundergoes mercerization/1/, being processing with a concentratedsolution of sodium hydroxide (NaOH), resulting in alkali cellulose,which afterwards is subjected to destruction/2/, i.e. aging, to decreasethe degree of polymerization. This is followed by temperaturereduction/3/ and dosing of the alkali cellulose amount for theproduction of one batch of viscose/4/. The next stage iscarbon-disulphide treatment during which the alkali cellulose totransforms into cellulose xanthate/5/, whose most important property isthat it is soluble>in diluted solutions of sodium hydroxide/6/. Thecellulose solution of one batch is mixed and homogenized with the onefrom the previous and the following hatch/7/, deaerated/7/, and filteredseveral times to remove the impurities/8/. Then the viscose solution,with is passed through a viscose pipe collector/38, FIG. 3/ underpressure'to the spinnerets of the spinning machine/10/ for spinning.

According to the method of the invention, constantly synchronizatedviscose, solution supplying/feeding/ and spinning devices actuation fora definite type of rayon is interrupted/FIG. 4/, as, first /27-1 andsecond /28-1/spinning devices land arranging freshly spun yarn incentrifuge /29-1/ system /39-5/are actuated by the use of existing powerfeeding installation /40-4, motors /40-1 and 40-2/and reduction geargroups/39-1, 39-3 and 39-4/ named as the first power feeding andactuating installation. According to the method of the invention newpower feeding /40-7/and actuating installation/40-3 and 39-2/ is addedto the same spinning machine named second power feeding and actuatinginstallation which work runs by a control unit and by the use of whichpower shaft/21/ and joined to it viscose solution dozing pumps/22/ canbe actuated independently of first /27-1/and second /28-1/spinningdevices actuation. According to the invention power shaft/21/ actuationdo not depends on spinning/27-1 and 28-1/ and arranging freshly-spunfilament rayon devices/39-5/ actuation anymore and quantity of viscosesolution dozed to the spinnerets for spinning could be changedindependently of spinning and arranging devices work.

The viscose solution coming out from the spinnerets enters a spinbath/11/, where as a result of the chemical reactions in coursetransforms into rayon filament fibers.

Leaving the spin bath/11/the freshly-spun cellulose filament fibers arepassed to the located at each working position first /27-1/and thensecond /28-1/ spinning devices, and then transported and arranged in thecentrifuge at the same working position/29-1/. When the centrifuge isfilled up to a specific volume, the filament fiber between the first andthe second spinning devices is cut off and wound only on the first one.Meanwhile the centrifuge is stopped, the formed in it rayon cake istaken out, and the centrifuge is again put into operation. When the sameis in operating mode, the fiber from the first spinning device is againtransferred to the second one, and then passed into the centrifuge toobtain the next rayon cake.

This is followed by washing procedures where the freshly-spun viscoserayon is treated with various solutions to clear the residues of thespin bath, the sodium sulfate and sulfur resulted from the chemicalreactions during spinning. The obtained semi-finished product is thendried, conditioned, rewound, prepared for quality control inspection andpackaging as a finished product.

The method of production of dyed in mass viscose filament rayon withcyclically varying thickness/linear density involves mixing of theviscose solution with a preliminary prepared pigment suspension,consisting of one or a couple of pigments, homogenization of the mixturewhere the pigment particles are uniformly distributed throughout theentire volume of this solution, which afterwards is fed for spinning andthe stages as above described process according to the inventionfollowed by the next already known operations.

Thus after the interruption of the classical actuation of the powershaft and its transformation to actuation with an additionally mountedmotor with loaded into new control unit program in all working positionssimultaneously and synchronously viscose filament rayon is being spunwith cyclically varying thickness/linear density.

The installation for the production of filament yarn with cyclicallyvarying thickness/linear density—named flame viscose filament rayon)according to the invention includes the following stages and unitsconsecutively connected as: mercerization unit, aging unit, unit fortemperature reduction, a dosing unit for the amount of the alkalicellulose needed for the production of one batch of rayon;carbon-disulphide treatment unit, units for mixing of the cellulosesolution from one batch to the one from the previous and the followingbatch to homogenization and for deaeration, filtering unit for removalof the impurities, a pipe collector to the spinning machine to which arange of working positions are added, each of them equipped with a firstand a second spinning devices and a centrifuge where to obtain a rayoncake. In this arrangement, the first electric motor, through the firstreduction gear and gear transmission system, is connected for actuationof the first and the second spinning devices, and the second electricmotor powers the arranging device to the first centrifuge. The first andthe second electric motors are powered by the first power feeding unit

According to the invention a second power feeding installation is addedincludes a new third electric motor powered b the new second powerfeeding unit, connected to an inverter control system, which through anadditional reduction gear group is connected to the power shaft andactuating the viscose solution dosing pumps only.

In the control unit a preliminary invented operation program is setwhich defines the frequency and range of change of the revolutions ofthe power shaft actuating the viscose dozing pumps independently fromthe operation of the other spinning devices. The dozing pumps revolutiondeviations change the cellulose solution quantity supplied for spinningand, as a result of this, also the thickness; linear density of the spunrayon filament fiber. With the invented program and added new elementsof the machine can be achieved cyclically repeating sections of thefilament rayon with varying thickness and different length of the same,obtaining various effects in the freshly spun Viscose filament rayondirectly during the spinning process which are stable in finishedfilament rayon itself and articles by its use done.

Further, freshly spun filament yarn with cyclically varying lineardensity is passing through already described following units: washingoperations unit where the freshly-spun viscose rayon is treated withdifferent solutions for removal of the impurities resulting from thespin bath and the chemical reactions during spinning, unit forcentrifugation of the semi-finished product, drying unit, conditioningunit, rewinding unit, quality control unit (18,19) and storage unit(20).

The installation for the production of dyed M mass filament earn withcyclically varying thickness/linear density (flame viscose rayon),includes an added to the described up construction of the spinningmachine an individual or group dyeing installation. It includes astorage tank for a preliminarily prepared pigment suspension, addedpigment suspension dosing pump and a homogenizer connected to theexisting viscose pipe collector from which through the dosing pumps thedyed in mass viscose solution is fed for spinning to the spinnerets ofthe spinning machine, to which are connected the above-described,according to the invention, first power feeding installation with itspertaining devices, and invented new second power feeding installationwith its pertaining devices.

The only particularity in this installation is that the viscose solutionfrom the main pipeline, before being passed to the viscose pipecollector, is fed to the homogenizer. Again in the homogenizer, thepigment suspension is introduced from the tank dosed by means of apigment suspension dosing pump. The viscose solution and the suspensionare mixed and homogenized, and then passed to the viscose pipe collectorpart of spinning machine. From there the already dyed solution by theuse of viscose dosing pumps is fed for spinning to the spinnerets. Thedyed in mass viscose solution coming out from the spinnerets enters aspin bath, where as a result the chemical reactions in course istransformed in fibers. Considering that the revolutions of the powershaft are not constant but are under changes depending on the programset in the control unit, the final result of this spinning according tothe invention is dyed in mass viscose filament yarn with cyclicallyvarying linear density/thickness so called (flame) dyed in mass filamentrayon.

Leaving the spin bath, the freshly-spun cellulose as filament fiberspasses consecutively to the first and the the second spinning device,and then arranged in the centrifuge. When the centrifuge is filled up toa specific volume, the fiber between the first and the second spinningdevices for each working position is interrupted and wound only on thefirst spinning device. Meanwhile the centrifuge is stopped, the formedin it rayon cake is taken out, and the centrifuge is again put intooperation. When the same enters in operating mode, the fiber from thefirst spinning device is again transferred to the second one and thenpassed into the centrifuge to start the production of the next rayoncake.

This is followed by washing procedures where the freshly-spun viscosefilament rayon with cyclically varying thickness is treated with varioussolutions to clear the residues of the spin bath, the sodium sulfate andsulfur resulted from the chemical reactions during spinning. Theobtained semi-finished product is then dried, conditioned, rewound,quality control and packaging as a finished product.

The same installation and method are applicable in the production ofbicolour filament rayon with cyclically varying thickness/linear density(flame) viscose rayon. This installation, according to the invention,includes an added to the first a second pipe collector for viscose,powered by the same motor actuating the first and operatingsynchronously with it. The second viscose pipe collector is connected toa second individually operating dyeing installation, as the dosing pumpssupplying viscose for spinning to the spinnerets, for each pair ofworking positions are fed with viscose for spinning from the separateviscose pipe collectors in the following way: a dosing pump at the firstworking position is supplied with viscose from the first pipe collector,and the neighbouring one, i.e. second working position dosing pump, isfed with viscose by the second pipe collector. The same is then repeatedfor each successive pair of working positions. Thus, on the half of theneighbouring working positions a viscose solution in one colour is spun,and on the rest—a viscose solution in a different colour, thus obtainingdifferently dyed viscose filament fiber. Due to the program set in thecontrol unit, apart from being coloured differently, the filament fiberswill also be with cyclically varying thickness/linear density.

In addition, according to the invention, the spun on the neighbouringworking positions differently dyed in mass rayon filament fiber insteadof being separately taken by the first and second spinning devices arejoined together only to the first spinning device of first workingpositions. After that, the two differently dyed and already combinedfibers are transferred together to the second spinning device at thefirst working position and then to the centrifuge at the same firstworking position. The result of this innovative way of spinning is thatthe bicolor and (flame) filament yarn is obtained directly as early asthe stage of the first spinning device and later a viscose filamentrayon with cyclically varying thickness linear density and dyed in twocolours as cake is taken out from centrifuge.

The application of this innovative scheme of power shaft actuatingenables a scheduled change in the quantity of the supplied for spinningcellulose solution independently from the operation of the otherspinning devices, and respectively a cyclically changes of the lineardensity/thickness/ of the viscose rayon filament fiber.

An advantage of the method and installation suggested is the directproduction of raw white bright or dyed in mass viscose filament rayonwith cyclical variation of its linear density/thickness, i.e. flameviscose filament rayon.

SHORT DESCRIPTION OF THE FIGURES ENCLOSED

FIG. 1 illustrates the sequence of the processes in the classicalproduction of raw white bright or dyed in mass viscose filament rayon.

FIG. 2 presents the classical unit structure of installation 10-1, i.e.the installation performing the dyeing in mass of the viscose filamentrayon

FIG. 3 illustrates a design of the classical actuation of the spinningmachine for the production of raw white bright or dyed in mass viscoserayon filament rayon with uniform thickness/linear density.

FIG. 4 presents the actuation of the spinning machine according to theinvention.

FIG. 5 illustrates the variation of the linear density/thickness/of theviscose filament rayon from one cake, whose spinning is performedfollowing the classical spinning procedure i.e. of the actuation of thespinning machine's units. On the abscissa is marked the rayon fiberlength of investigated rayon cake, and the ordinate (Y-axis) shows thevariation of the fiber linear density/thickness presented in tex. Thisfigure gives a clear concept of the way the rayon fibre thicknesschanges from start to the end of a centrifugal filament rayon cake usingthe classical spinning procedure.

FIG. 6 illustrates the variation of the linear density/thickness of aviscose filament rayon filament from cake whose spinning follows theinnovative method and actuation procedure of the spinning machine'sunits according to the invention.

FIG. 7 illustrates the installation, which added to FIG. 4, enables theproduction of bicolour rayon with cyclically varying thickness(flameone) simultaneously.

MODEL PERFORMANCE OF THE INVENTION

The installation for the production of raw white bright or dyed in massviscose filament rayon presented on FIG. 1 includes the following,units, consecutively connected following the technological operationsas: unit 1 for mercerization—treatment of the initial pulp (cellulose)with a concentrated solution of sodium hydroxide, unit 2—for aging, hereas a result of the process of destruction alkali cellulose is obtained,i.e. the degree of polymerization is decreased, unit 3—temperaturereduction, unit 4—dosing of the alkali cellulose amount for theproduction of one batch of viscose, unit 5—for carbon-disulphidetreatment of the alkali cellulose to obtain cellulose xanthate, units 6and 7 for mixing and homogenization of the cellulose solution of onebatch to the one from the previous and the following batch and deaeration, unit 8—filtering to remove the impurities.

Unit 9, for the preparation of a dyeing suspension and unit 10-1 forviscose solution dyeing could be connected to spinning machine 10 ifdyed in mass rayon filament rayon have to be produced. After thespinning, the freshly-spun viscose rayon is treated in unit 12 withvarious solutions, prepared in unit 13 to remove the residues from thespin bath and chemical reactions after the spinning.

Further, following the technology serially connected are units 14, 15,16, 17 and 18 for centrifugation, drying, conditioning, rewinding,quality control inspection and packing as finished production 19 to bestored in unit 20.

In order to obtain dyed in mass filament rayon, to the spinning machine10 an individual dyeing installation 10-1 is connected. As shown in FIG.2, it includes a pigment suspension storage tank 30, pigment suspensiondosing pump 31, a control unit 34 for the dosing pump 31 control ahomogenizer 32, where the pigment or pigments particles have to be mixeswith viscose solution and distributed uniformly throughout the entirevolume of it; reduction geared electromotors 35 which guarantee thecomponents mixing inside of homogenizer 32 and suspension circulation insuspension storage tank/30/. From the main pipe collector 36 thecellulose solution passes into the homogenizer 32 through the localviscose pipeline 37 and flow meter 33. The already dyed after thehomogenization solution fills up under pressure the local viscose pipecollector 38, which supplies dyed in mass viscose to all the workingpositions of the spinning machine 10.

According to FIG. 4 for the actuation of the spinning machine are usedtwo independent from each other power feeding units as follows: feedingunit 40-4 powers the first and the second electric motors 40-1 and 40-2,as motor 40-1 through reduction gear 39-1 and the gear transmissionsystem 39-3 continues actuating the first 27-1 and second 28-1 spinningdevices, and the motor 40-2 through reduction gear 39-4 keeps actuatingthe fiber arranging in the centrifuge 29-1 device 39-5 of the spinningmachine 10. According to the invention is added a third electric motor40-3, powered by a second feeding unit 40-7, as the electric motor 40-3,which through reduction gear 39-2 actuates the power shaft 21 and theviscose solution dosing pump 22 joined to it. According to theinvention, the third electric motor operation is controlled by thecontrol units 42 and 40-7.

Thus, the actuation of the power shaft 21 is performed independentlyfrom the powering of the spinning devices 27-1 and 28-1. In accordancewith the program set in the control units 42 and 40-7, a change of therevolutions of the power shaft takes place—when the number ofrevolutions is higher, a greater amount of viscose is being dosed, sothe fiber spun will be thicker. Oppositely when the number of powershaft revolutions is lower, a smaller amount of the solution to be spunwill result in a thinner fiber. The result from thealternation—higher/lower solution fed for spinning, according to theinvented method and program set in control unit 42, is the production ofviscose filament rayon with a cyclically varying thickness/lineardensity/without the number of filaments changes.

Example if the classical scheme of spinning devices including powershaft actuating is under use the spinning will run with constantquantity of viscose solution dozed from dozing pumps and transferredfrom local pipe collector to the spinnerets for spinning. This quantitysupplied for spinning will be around 22 grams per minute and is aconstant for the whole production cycle of 33.0 tex for example. Theresult of this classical production behaviour, where power shaft andother spinning devices actuation is strongly connected is production of33.0 tex with actual count between 33.4 till 35.3 because of centrifugalway of spinning presented on FIG. 5.

If actuating scheme is under use and actuating of power shaft isindependent from other spinning devises according innovation and programin control unit 42 set power shaft revolutions could be cyclicallychanged from 8 to 24 turns and respectively the quantity of viscosesolution fed for spinning will cyclically range between 7 and 30 gramsper minute. The result of this innovative way of viscose solution dozingfor winning is production of 33.0 tex filament rayon with cyclicallyvanilla thickness between 18.0 till 35.0 tex presented on FIG. 6.

In the production of dyed in mass viscose filament rayon with cyclicallyvarying thickness, the prepared viscose solution from pipeline 37 beforebeing fed under pressure through flow meter 33 in the pipe collector 38of the spinning machine is supplied to the homogenizer 32 of theinstallation for the production of dyed in mass viscose filament rayon.The preliminarily prepared pigment suspension, which for the time of theproduction cycle is stored in tank 30 (FIG. 2) is dosed by pump 31 tothe viscose solution before the same is passed to the homogenizer 32(FIG. 2). In the homogenizer 32 the viscose solution is mixed with thedosed by pump 31 suspension thus causing the pigment particles todistribute uniformly throughout its entire volume. The already dyedafter homogenization viscose solution is again fed under pressure to thelocal viscose pipe collector 38 of the spinning machine /FIG. 2/, towhich the solution dosing, pumps have been added. The quantity of thealready dyed in mass viscose supplied to the spinnerets for spinning iscontrolled by the program set in the control unit 42. Based on thisprogram, the frequency inverter part of control unit 42 operate themotor 40-3, which through reduction gear 39-2 and the connection 41-7actuates the power shaft 21 and respectively the viscose dosing pumps22. When the number of revs of the power shall is higher, a greateramount of viscose is dosed and the fiber spun is thicker, and when thenumber of power shaft revs are lower the spun fiber is thinner. Thus,dyed in mass viscose filament rayon with cyclical change of the lineardensity /thickness/ is obtained, where linear density cyclicallydeviation depends on the type of program set in the control unit 42.

Further, the installation operates in the already known way: in unit 12the freshly-spun viscose filament rayon is treated with varioussolutions prepared in unit 13 for removal of the residues of the spinbath, the sodium sulfate and sulfur resulted from the chemical reactionsduring spinning.

The obtained semi-finished product is centrifuged, conditioned rewoundand prepared for quality control inspection and packaging as finishedproduction—units 14, 15, 16, 17, 18, 19 and after quality inspectionstored in unit 20.

In control unit 42 can be installed various programs for the operationcontrol of the third electric motor 40-3, which practically enhances thepossibilities for production of different types of viscose filamentrayon with cyclically variation of thickness, i.e. differently (flamed).

With the new product, a wide range of items is created of a new fancyarticle preparing—viscose filament rayon yarn with cyclically variationof the linear density /thickness/ along the fiber length with uniqueeffects.

1. A method for obtaining viscose filament rayon with cyclically varyingthickness, including the following stages: mercerization of initial pulpi.e. processing with a concentrated solution of sodium hydroxide,resulting in alkali cellulose, which afterwards undergoes the process ofdestruction to decrease the cellulose degree of polymerization, followedby temperature reduction and dosing of the alkali cellulose amount forthe production of one batch of viscose; carbon-disulphide treatmentwhich causes the alkali cellulose to transform into cellulose xanthate;the cellulose solution of one batch is then mixed and homogenized withthe one from the previous and the following batch and deaerated,filtered to remove the impurities; then the viscose solution is fed forspinning to the spinning machine, as the viscose solution coming outfrom the spinnerets enters the spin bath where as a result of thechemical reactions in course transforms into filament fibres which arepassed through spinning devices to a centrifuge at each working positionin order a rayon cake to be formed; With the main characteristic thatthe spinning is performed by interrupting the synchronization of theviscose solution supply to the spinnerets of spinning machine and thetakeover of the freshly-spun in the spin bath filament rayon byseparately actuating of the first and the second spinning devices andthe rayon arranging in centrifuge device using the existing first powerfeeding installation, and separately actuation and control of the powershaft and viscose dozing pump joined to it by using new second powerfeeding installation, run by a control unit (inverter) thus carrying outa programmed change of the quantity of the supplied for spinning viscoseindependently from the operation of the first and second spinning andetc., devices of the spinning machine.
 2. A method for obtaining dyed inmass viscose filament rayon with cyclically varying thickness/lineardensity according to claim 1, with the main characteristic that viscosesolution before spinning is mixed with preliminarily prepared pigmentsuspension from one of a couple of dispersed in water organic pigmentsprepared as pastes; homogenization of the mixture, which is passed forthe same way of spinning as claim 1 and all other stages of theabove-described processes.
 3. A method for obtaining bicolour dyed inmass viscose filament rayon with cyclically varying thickness/lineardensity according to claim 1, with the main characteristic that to thespinning machine are added two independently operating installations fordying in mass by the use of which viscose solution before spinning couldbe coloured by two preliminary prepared different in colour pigmentsuspensions. By the use of two homogenizers and two local viscose pipecollectors to the neighbour working positions of spinning machine at thesame time could be supplied differently coloured viscose solutions forspinning. After spinning differently coloured freshly spun filamentfibers from these two working positions are transferred to the firstworking position centrifuge only by the use of first and second spinningdevices of the same first working position. After spinning as claim 1freshly spun bicolour filament rayon with cyclically varying thicknessis passing through all other stages of the above described processes. 4.An installation for the production of viscose filament rayon withcyclically varying thickness, added to the existing spinning machinepart of which are local viscose pipe collector (38) to which a range ofworking positions are joined each one supplied with viscose solutiondozing pumps, power shaft actuating viscose dozing pumps, first andsecond spinning devices (27,28), an arranging system (39-5) by whichfreshly spun filament rayon is transferred from second spinning device(28) to the centrifuge (29) where freshly spun cake is obtained, twoelectric motors 40-1 and 40-2 powered by electricity from first feedingunit 40-4 and actuating as follows: first electric motor 40-1 throughthe first reduction gear 39-1 and a gear transmission system 39-3 isconnected for actuation of first 27-1 and the second 28-1 spinningdevices as the second electric motor (40-2) is actuating the arrangingdevice 39-5 with the main characteristic that a second power feedinginstallation is added consisting of a third electric motor (40-3),powered by electricity from the second feeding unit (40-7) and connectedto it a new control unit (42—controlling inverter system), as the thirdelectric motor through an additional reduction gear group (39-2) isactuating the power shaft (21) only and the viscose solution dosingpumps (22) both work of which is controlled by unit (42) according tothe preliminarily set into this unit program operating range of changesof the power shaft (21) and viscose dozing pumps; /22/revolutions,independently from the operation of the all other devices. The spinningon the spinning machine (10) is followed by all other stages of theabove-described processes from washing unit (12), till a storage unit(19).
 5. An installation for the production of dyed in mass viscosefilament rayon with cyclically varying thickness according to claim 2,with the main characteristic that to the spinning machine (10) anindividual installation for dying in mass (10-1) is joined, including astorage tank for a preliminarily prepared pigment suspension (30), asuspension dosing pump (31), a homogenizer (32(connected to the localviscose pipe collector of the spinning machine, to which are joined arange of working positions. Power shaft and all other spinning devicesactuating is arranged in accordance with scheme described in claim
 4. 6.An installation for the production of bicolour viscose filament rayonwith cyclically varying thickness according to claim 3, with the maincharacteristic that to the spinning machine (10) are joined twoindividual installations for dying in mass (10-1), with two storagetanks for preliminarily prepared pigment suspensions (30), including twosuspension dosing pumps 31 and two homogenizers 32 connected through twolocal viscose pipe collectors to one spinning machine with joined tothem a range of working positions. The actuation of viscose dozing pumpsindependently to which viscose pipe collectors are joined is arranged byone and the same power shaft (21) which operation follows the schemedescribed in Clam
 4. 7. Viscose filament rayon with cyclically varyingthickness/linear density obtained following the method and installationas described in claim
 1. 8. Viscose filament rayon dyed in mass withcyclically varying thickness/linear density obtained following themethod and installation as described in claim
 2. 9. Bicolour viscosefilament rayon with cyclically varying thickness/linear density obtainedfollowing the method and installation as described in claim 3.